Finishing, draining, and packing mechanism for centrifugal casting machines



M. T. SOSO Nov. 6, 1934.

FINISHING, DRAINING, AND PACKING MECHANISM Foa CENTRIFUGAL CASTING MACHINES Filed Sept. 5o, 1935 \NVENTOR /V/ 0 7 5 5o BY 2f/w ATTOR N EY Patented Nov. 6, 1934 FINI SHIN G,

MECHANISM FOR ING MACHINES DRAINING, AND P l1v c K I N G CENTRIFUGAL CAST- Marko T. Soso, Los Angeles, Calif. Application september so, 1933, serial No. 691,657

8 Claims.

This invention relatesto the casting of hollow objects from plastic materiaLsuch as of cement orconcret'e. The objects to be cast, may be pipe, posts or other hollow ware. l

The usual process is to impart rapid rotation to a cylindrical mold, and to feed. a wet mixture of the cement or concrete to the interior of `the mold. Centrifugal force throws the plastic ma terial to the walls of the mold. In order that 10 the material be distributed quite uniformly, and

to pack it, it has been necessary to` rotatethe` mold at high speeds, of the order of 400 revolutions per minute, and to make the mixture quite wet. However, at such speeds there is danger that the heavier constituents, such as the rock or gravel aggregatamay be thrown out toward the outer periphery, providing anon-homoge-` neous product. f

It is.one of the objects of this invention to make it possible to secure eiective packing of the plastic material, although the speed be as low as 200 revolutions per minute, for pipe of about three feet internal diameter.

In. .order to improve the quality of the cast product, it is necessary to remove the excess moisture, expressed from the plastic material. This moisture usually forms an overlying'layer on the interior surface of the cast product. The removal of this excess moisture, such as by `brushing or otherwiseacting on the surface of the product during or after the `molding operation, has beenattended with considerable difliculty. l

` `It is thus another object of the invention to make it possible to drain this excess moisture in a convenient and simple manner, and without the necessity of emptying receptacles used. vfor collecting the moisture.

It is still another object of the invention to provide a simple and inexpensive device for nishing or trowelling off the interior surface of the casting while it is plastic. This nishing off is important, because centrifugal castingsare made in molds having only` an exterior contact wall for the casting, the interior surface of the casting being formed in response to thel spreading action `of centrifugal force. For this reason, slight irregularities are apt to occur on the interior surface, which should be nished olf for providing a good grade of product, `free from surface porosities.

It is still another object of the ,invention to provide `a simple device that can accomplish simultaneouslyallv three functions of drainingA excess moisture, packing the plastic material, and finishing its interior surface. l. This invention possesses many other advantages, and has other objects which will be readily apparent from bodime'nt of` the `invention shown in the drawing accompanying and forming part of the" present specification. While a simple form arranged for manual operation has been shown, it will be evident to one skilled in the art, that the nishing, draining, and packing device can be combined in various Ways with other Aelements of existing machines; for examplait may be supported beneath or above a charging hopper which places revolving mold. The form shown will now be` described in detail, illustrating the general principles of the invention; but it `is to be `under-- stood that this detailed descriptionis not to be taken in a limiting sense, since the scope of the invention is best dened by the'appended claims Referring` to the drawing: Figure 1` is a` diagram showing the device inY section, and in use within the interior of a pipe being molded; '80 f1 Fig. 2 is a fragmentary sectional view taken along plane 2-2 of Fig. 1;

Fig. 3 is an enlargeddetail section taken along the plane 3-3 of Fig; 1; `and Fig. 4 is apictorial view of the apparatus. 85

Inthe present instance there is shown a centrifugal mold 1 of general cylindrical configuration and disposed on a horizontal axis. In order to rotate the mold at a rapid rate suflicient to utilize centrifugal force, a series of flanged roll- 905 ers such as 2, 3 can serve to engage the circular band or track 4, disposed on the outside of the mold 1. It is to be understood, howeventhat a plurality of spaced tracks 4 may be. used.

Only one `is shown in Fig. 2 since only one end 95 of the mold 1 is illustrated. The mold 1 may be` of the order of three feet in diameter and may be eight feet or more in length. i l By rotating one or more of the rollers 3 as by the aid ofthe shaft 5, the mold 1 is rotated 10o" about its horizontal axis. Wet plastic material such as concrete or cement cangbe fed into the i interior of the mold 1. Due to centrifugal action this plastic material is disposed to form an arti-V cle 6,such as hollow pipe.

1n the present instance the article 6 is shown as made for concrete and mold 1 can be rotated at the rate of about 200 revolutions per minute. After a definite "thickness of material is deposited to form the article 6, it is necessary to inish a consideration of the em- 60571 the wet plastic material in the 70l structure for. holding. them in spaced relation and paci: the article, as well as to collect the excess mixture exuding from the plastic material.

In order to accomplish this result, the mold 1 is kept rotating after the article 6 is formed. There is inserted into the interior of the molded article a device which performs the finishingand packing function; and also preferably the function of draining the water from the interior of the article 6. The finishing and packing is accomplished by contacting the interior surface l of article 6 with a pair of members '7 and 8. These elements contact the` interiorsurface and are spaced apart by a distance'slightly less than the interior diameter of article 6. In this way they contact at points which are at the extremities of a chord of the interior circle of article 6. For this purpose the elements '7 and 8 are supported in spaced relation and there is sufcientweight in the device to hold these contacting membersin .the position shown in Fig. 1, below the horizontal diameter of the article 6. 1

In, .the present instance, these contacting members 'Zand 8 are in theform of metal rollers is preferably inthe form of a shallow receptacle 9. -Thisreceptacle 9 has a converging bottom 10 and end members y11 and 12 between which the 1;.lrollers '7 and 8 are journalled. Ther manner inwwhich thebearings are provided for. the

rollersis shownto :best advantagein Fig. 3. In that case it is seen that. a roller bearing structure 13 .has its outer race supported in an in- '.terior recess in roller '7; andthe inner race is mounted on a shaft :14 passing through the rollers and held in;place as by the -internally threaded .member .15.1 .This interiorly `threaded member 15 engages external. threads on the exn :.tremity of shaft. 14, and canhave a fiat head 16 with a kerf 1'7.. The head-16 can be accommodated in an appropriate aperturen the end wall 11:0r .12.

The receptacle9 acts to collect .moisture from `;the interior wall of article 6 as the/mold. l is rotated. For .thispurposethe bottom 10 of the receptacle extends beneath each; of the rollers '7 and; 8. Thus .when mold -1 is rotatedl in a counterclockwise direction; as indicatedy by arf row 18 .of1Figr 1, roller' is also rotated in a counterclockwise .direction .and .wa-ter. Vfrom the interiorsurface of farticle .6r is captured on the outeryperiphery. of roller; 8 andzis discharged into the :receptacle 9. Someof the .water :may

.- accumulate Abeneath the'lineof contact between rollerv 8 andy the interior. vsurfaceof article 6.

From this positionit can flow intothe collection receptacle'Q, as indicated by the arrows 19.

Further excess moisture canbe collected in'a .similarI manner. by they actionA of 'roller I7. In this case theroller .'7. is also. rotated in a counterclockwiseydirection, the water vcollecting above the roller '7 and between the roller '7 and` the inner surfacerof article is thrown up against a -circular guard or shield 20. -This shield reflects thewater downwardly as -indicated by the arrovv.21 into .ther-receptacle 9. There is sufficient weight'imposed uponthe receptacle 9 to keep rollers :'l and 8 in relatively horizontal position; and this weight also acts. to impart a packing action' through `the intermediary of the rollers '7 and 8 on .theinside of article 6.

It is apparent that the'y device including the receptacle 9 andthe rollers Tand is supported i at the. points of contact betweenthe'rollers '1f-and 8 and the interior of article 6. In this way the rollers act as smoothers and trowellers to finish the interior surface and to reduce porosity and irregularities in it.

The insertion of the device is simple. It can be done by hand, as by merely lifting it into the article 6 and letting it rest by gravity in the position shown. When so placed inside the article 6, it can be manipulated by hand to traverse the whole length of the article 6. Several back and forth motions may be necessary to secure a fully finished and packed product.

In'order to drain the collected moisture from receptacle .9, a drain pipe 22 can be provided leading at a downward slant from the bottom l0 of the receptacle 9 to the exterior of the mold 1. Thus pipe 22 can have a slot cut in it im- `mediately'belcwthe receptacle 9 and in registry tension 24 which may effectively serve as a han dlefor-manipulating the device in its back and forth'travel inside of article 6. .If desired, another handle member 25 (Fig. 2) can be coupled to the inner end of the receptacle 9 so that it may .be manipulated from the other end of the l mold 1.

It is of course to beV understood. .that the de.

vice including receptacle 9 and rollers 7 and8 can lbe readily removed by hand from thearticle 6 whenever the operations of draining, finishing and packing are completed. When this-is done, the lrotation of mold 1 can bevstoppedand the article 6 removed therefrom.. Upon use. of the device as described, it is possible to pack the plastic material very eifectively vand to collect the excess moisture in a simple `and rapid manner. This can also be accomplished at a `com-y paratively low rate of rotation for a mold 1.

I claim:

1. In a device for operating upon the interior surface of a hollow cylindrical .article cast centrifugally from plastic material, the axis of said article'being non-vertical, a pair of surfacecontacting means, and a support for spacing. said means at a distance such that the surfacecontacting means rest by gravity below the interior diameter of the.- article, and upon the interior surface thereof.

2. 'Ina device for operating upon the interior. surface of -a hollow cylindrical article cast .centrifugally from plastic material, the axis of said yarticle being non-vertical, a pair of rollers .ar-

ranged to contact the interior surface of the article, and a support for spacing said rollers to permit them to rest by gravity below the-interior diameter of the article, and upon the interior surface thereof.

3. In a device for operating upon the interior surface of a hollow cylindrical article cast centrifugally from plastic material, the axis of said article being non-vertical, a moisture collecting receptacle adapted to be inserted in the article and to be .supported thereby before it has set and during rotation thereof, and a pair of surface contacting means spaced on said receptacle for contacting with the interior surface of the article.

4. In a device for operating upon the interior surface of a hollow cylindrical article cast centrifugally from plastic material, thenaxis of said article being non-vertical, a moisture collecting receptacle adapted to be inserted in the article vbefore it has set and during rotation thereof, and a pair of parallel rollers spacedpn said recep- `face of the article, and for supporting said receptacle therein, and a drain leading from the receptacle to the exterior of the article.

6. In a device for operating upon the interior surface of a hollow cylindrical article cast centrifugally from plastic material, a moisture collecting receptacle adapted to be inserted in the article before it has set and during rotation thereof, a pair of surface contacting means spaced on said receptacle for contacting with the interior surface of the article, and a shield above one of the surface contacting means for guiding the Water expressed by said means into the receptacle.

7. In a device of the character described, a receptacle, and a pair of parallel finishing and packing rollers arranged on opposite sides of the receptacle, and above the bottom thereof, for

causing the receptacle to collect moisture ex-` pressed by the rollers. l

8. In a device of the character described, a receptacle, a pair of parallel finishing and packing rollers arranged on opposite sides of the receptacle, and above the bottom thereof, for causing the receptacle to collect moisture expressed by the rollers, and a drain pipe leading from the bottom of the receptacle.

MARKO T. SOSO. 

